It probably won’t come as a shock to you that as I was writing up my last post on IoT and my new Geiger counter I was mentally reviewing all the things that scared the crap out of me had me concerned security-wise. I don’t mean the apocalyptic visions of Fallout, but about the fact that I have a device I don’t necessarily trust sitting on my network constantly feeding data to a remote server without much control by me.

I’m predictable like that.

Upon further review I realized I wanted to write up my thoughts on how I would protect against such an unknown, but really… you just need to stick it on an isolated network. You can’t see me, and I can’t see you. I’ll leave it to the networking wonks to decide what isolated really means in this case.

That of course left me with a very short and very boring post.

It then occurred to me that I’ve never really written in detail about different types of threats or risks or how you model them when developing a system. Of course, I don’t want to write in detail about different types of threats — there’s plenty of content out there already about this sort of thing. What I do want to do though is talk about how you model the risks so you can work through all the potential threats that might exist.

In keeping with the theme (because it’s fun and highly improbable) we’re going to build a fictitious radiation monitoring system just like the uRADMonitor, but we’re going to look at how you would evaluate the risks to such a system and how you might mitigate them.

Disclaimer
I don’t have any affiliation with the uRADMonitor project aside from the fact that I have a device of theirs in my office on my network. I can’t speak to their motivation for building the system and I can’t say what they’ve done to protect their system. This is purely a thought experiment on how I would build and protect a similar system.

Additionally, this is not necessarily a model where I’ve listed every possible risk or threat and rigorously verified solutions work. In fact, I’ve left out a number of things to consider.

Remember: it’s just for fun.

Projects are created to solve particular problems (also, sky is blue: report). This monitoring network is no different. We’ll review the problem as we see it, and then we’ll create a design to solve the problem. We’ll then review the design and see what kinds of risks we might find and how we can solve for them as well. We’ll iterate on this a few times and hopefully come up with a secure solution.

Not surprisingly I’ll go off on tangents about things I find interesting and gloss over other things. They may not be pertinent to the discussion at all.

The Problem

Radiation levels affect the health and well being of the population. Sudden significant changes in levels can have dangerous health effects and indicate signs of environmental accidents or geopolitical unrest. An unbiased real time record of radiation levels needs to be created and monitored so appropriate actions can be taken in the event of serious danger.

The Solution

Build and deploy a distributed network of radiation monitoring agents that persist data to a central store so the data can be reviewed by analysts and automatically notify the appropriate people when significant events occur.

If you’ve ever done product design that cryptic answer might be all you need from the product owner. So we need to break that down a bit. We’ve got a whole bunch of agents distributed throughout the world sending data back to a central server. This data should be consumable by analysts (scientists, safety authorities, etc.) either through an API (a program might be analyzing the data), or through a graphical interface (an actual person wanting to review data). These are easy enough to develop — create writable web API’s for the agents, a web portal for the people, and read only web API’s for the programs.

Author Spotlight

Steve Syfuhs is a security software developer. He has spent the last few years building identity systems and is currently working at Kaseya as a Lead Member of the Technical Staff on the Identity and Access team after Scorpion Software was acquired. He has also been a Microsoft Developer Security MVP since 2011.